ATSAMD51J20A-AUT - 120MHz Cortex-M4F MCU, 1MB Flash | Microchip
MPN: ATSAMD51J20A-AUT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.67 | $5.67 |
| 10 | $5.21 | $52.10 |
| 100 | $4.62 | $462.00 |
| 500 | $4.18 | $2,090.00 |
| 1,000 | $3.74 | $3,740.00 |
| 2,500 | $3.32 | $8,300.00 |
ATSAMD51J20A-AUT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, volatile memory (SRAM), non-volatile memory (Flash), and a rich set of peripherals such as timers, ADC/DAC, communication interfaces (SERCOM), and GPIO. Within the broader taxonomy, the ATSAMD51J20A-AUT sits in the Cortex-M4F class (mid-to-high performance, DSP + FPU) above Cortex-M0/M0+ entry MCUs and below Cortex-M7 high-end parts. SAM D51 specifically adds hardware floating-point, a 120 MHz bus matrix, and up to two ADCs with up to 12-bit resolution at 1 MSPS, plus a high-speed USB and SD/MMC host on larger pin-count variants.
Key features include the Cortex-M4F core with FPU and DSP extensions, 1 MB dual-bank Flash supporting live update, 256 KB SRAM, a 12-bit 1 MSPS ADC, up to 2x 12-bit DAC, multiple SERCOM (USART/SPI/I2C configurable) channels, 32-bit RTC, and a full-speed USB 2.0 device/host controller with on-chip transceiver. Peripherals are connected via an AHB-APB bus matrix with separate DMAs for CPU offload. The device operates from 1.71V to 3.63V VDD with separate VDDIO rails for SERCOM I/O level shifting.
Architecture-wise, the SAM D51 uses a 2-layer AHB matrix with two SRAM blocks for predictable interrupt response, an event system for zero-latency inter-peripheral signaling, and a separate low-power backup domain containing a 32 kHz oscillator and RTC. The Cortex-M4F core is paired with a single-precision FPU and a complete DSP instruction set (MAC, SIMD), enabling audio processing, motor control algorithms, and digital filtering at the edge without an external DSP.
Typical applications include USB-CDC/HID peripherals, IoT edge devices with TLS stacks, audio processing (PDM/SAI interfaces, sample rate conversion), industrial motor control via PWM + ADC, butterfly estimation, USB CDC/serial device outputs, industrial motor control via PWM + ADC, USB CDC/serial output, USB-C HID human-interface devices (keyboards, touch panels), and low-power battery sensors with RTC-based sleep/wake. The wide SRAM and dual-bank Flash make it well suited to OTA-upgradable firmware.
When designing with this device, allocate a minimum of 4 KB Flash for the bootloader if you plan to use the SAM-BA or UF2 bootloader. Decouple VDD and VDDIO pins separately and place a 1uF + 100nF pair within 5 mm of each supply pin. For USB applications, route D+/D- as a 90-ohm differential pair and tie the VBUS sense to a GPIO via a voltage divider. Always configure unused pins as outputs or enable the input disable register to avoid parasitic current draw.
This page synthesizes distributor pricing, drop-in alternatives from the SAM D51 family, recommended peripheral companions, and practical engineering notes not found in the bare manufacturer datasheet.
Drop-in alternatives for ATSAMD51J20A-AUT — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with ATSAMD51J20A-AUT (same form factor and footprint) — differing in ADC, SRAM, USB, Package, DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
ATSAMD51J20A-AU
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →ATSAMD51J19A-AUT-EFP
✅ Drop-In✓ In Stock
$4.45 / Unit
View Datasheet →ATSAMD51J18A-AUT
✅ Drop-In✓ In Stock
$4.78 / Unit
View Datasheet →ATSAMD51J20A-AUT Maximum Ratings & Electrical Characteristics
| Core Architecture | ARM Cortex-M4F with single-precision FPU and DSP extensions |
| Maximum CPU Clock | 120 MHz |
| Program Flash Memory | 1 MB (1024 KB), dual-panel with ECC |
| SRAM | 256 KB with ECC |
| Package | 64-pin TQFP (10x10 mm) |
| Supply Voltage (VDD) | 1.71 V to 3.63 V |
| Operating Temperature Grade | -40C to +85C (-AUT suffix, automotive grade) |
| ADC | Up to 2x 12-bit, 1 MSPS |
| DAC | Up to 2x 12-bit |
| USB | Full-Speed USB 2.0 Device/Host with on-chip transceiver |
| Communication Interfaces (SERCOM) | Up to 8 configurable (USART/SPI/I2C/LIN) |
| Timers/Counters | TCC (24-bit PWM), TC (16-bit), RTC 32-bit |
| DMA Channels | Up to 32 channels |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
ATSAMD51J20A-AUT Pin Configuration
| Pin 1 | VDDIO — I/O supply voltage |
| Pin 2 | PA00 — GPIO / SERCOM / ADC |
| Pin 3 | PA01 — GPIO / SERCOM / ADC |
| Pin 4 | PA02 — GPIO / SERCOM / ADC / DAC |
| Pin 5 | PA03 — GPIO / SERCOM / ADC / DAC |
| Pin 6 | GND — Ground |
| Pin 7 | PA04 — GPIO / SERCOM / ADC / VREFA |
| Pin 8 | PA05 — GPIO / SERCOM / ADC / VREFB |
| Pin 9 | PA06 — GPIO / SERCOM / ADC |
| Pin 10 | PA07 — GPIO / SERCOM / ADC |
| Pin 11 | VDDIO — I/O supply voltage |
| Pin 12 | VDD — Core supply voltage |
| Pin 13 | PA08 — GPIO / SERCOM / NRESET |
| Pin 14 | PA09 — GPIO / SERCOM |
| Pin 15 | PA10 — GPIO / SERCOM |
| Pin 16 | PA11 — GPIO / SERCOM |
| Pin 17 | PA12 — GPIO / SERCOM |
| Pin 18 | PA13 — GPIO / SERCOM |
| Pin 19 | PA14 — GPIO / SERCOM |
| Pin 20 | PA15 — GPIO / SERCOM |
| Pin 21 | PA16 — GPIO / SERCOM |
| Pin 22 | PA17 — GPIO / SERCOM |
| Pin 23 | PA18 — GPIO / SERCOM |
| Pin 24 | PA19 — GPIO / SERCOM |
| Pin 25 | PA20 — GPIO / SERCOM |
| Pin 26 | PA21 — GPIO / SERCOM |
| Pin 27 | PA22 — GPIO / SERCOM |
| Pin 28 | PA23 — GPIO / SERCOM |
| Pin 29 | PA24 — GPIO / SERCOM / USB DM |
| Pin 30 | PA25 — GPIO / SERCOM / USB DP |
| Pin 31 | GND — Ground |
| Pin 32 | VDDIO — I/O supply voltage |
| Pin 33 | VDD — Core supply voltage |
| Pin 34 | PB00 — GPIO / SERCOM |
| Pin 35 | PB01 — GPIO / SERCOM |
| Pin 36 | PB02 — GPIO / SERCOM / ADC |
| Pin 37 | PB03 — GPIO / SERCOM / ADC |
| Pin 38 | PB04 — GPIO / SERCOM / ADC |
| Pin 39 | PB05 — GPIO / SERCOM / ADC |
| Pin 40 | PB06 — GPIO / SERCOM / ADC |
| Pin 41 | PB07 — GPIO / SERCOM / ADC |
| Pin 42 | PB08 — GPIO / SERCOM |
| Pin 43 | PB09 — GPIO / SERCOM |
| Pin 44 | PB10 — GPIO / SERCOM |
| Pin 45 | PB11 — GPIO / SERCOM |
| Pin 46 | PB12 — GPIO / SERCOM / NCS |
| Pin 47 | PB13 — GPIO / SERCOM |
| Pin 48 | PB14 — GPIO / SERCOM |
| Pin 49 | PB15 — GPIO / SERCOM |
| Pin 50 | PB16 — GPIO / SERCOM |
| Pin 51 | PB17 — GPIO / SERCOM |
| Pin 52 | PB18 — GPIO / SERCOM |
| Pin 53 | PB19 — GPIO / SERCOM |
| Pin 54 | PB20 — GPIO / SERCOM |
| Pin 55 | PB21 — GPIO / SERCOM |
| Pin 56 | PB22 — GPIO / SERCOM |
| Pin 57 | PB23 — GPIO / SERCOM |
| Pin 58 | PB24 — GPIO / SERCOM |
| Pin 59 | PB25 — GPIO / SERCOM |
| Pin 60 | GND — Ground |
| Pin 61 | VDDIO — I/O supply voltage |
| Pin 62 | VDD — Core supply voltage |
| Pin 63 | PA30 — GPIO / SERCOM / SWDIO |
| Pin 64 | PA31 — GPIO / SERCOM / SWCLK |
Typical Applications
ATSAMD51J20A-AUT is suitable for 7 applications: USB Human Interface Device (HID), Industrial Motor Control (FOC), Audio Processing and PDM Microphones, IoT Edge Sensor with TLS Stack, Automotive Body Control Module, Industrial Touch Panel HMI, Data Logger with SD Card Storage.
USB Human Interface Device (HID)
The ATSAMD51J20A-AUT is ideal for USB HID peripherals such as keyboards, mice, touch panels, and HID-class industrial controllers because it integrates a Full-Speed USB 2.0 device controller with on-chip transceiver on the 64-TQFP variant. With 120 MHz Cortex-M4F performance, USB HID polling is trivial at 1 ms bInterval, while the remaining 1 MB Flash and 256 KB SRAM easily hold the HID stack plus application code, plus a UF2 or SAM-BA bootloader. Compared to lower-end Cortex-M0+ MCUs, the M4F core runs HID stacks like TinyUSB at under 20% CPU, leaving headroom for matrix scanning and LED PWM via the TCC peripheral.
Recommended
Industrial Motor Control (FOC)
For sensorless or encoder-based Field-Oriented Control of BLDC/PMSM motors, the ATSAMD51J20A-AUT delivers 120 MHz Cortex-M4F performance with hardware FPU and DSP extensions, executing FOC loops well within the typical 20 kHz PWM cycle. The TCC channels provide 24-bit complementary PWM with dead-time insertion and hardware fault shutdown, and the dual 12-bit 1 MSPS ADCs can sample phase currents simultaneously. The 256 KB SRAM holds a full motor model including observer state variables without spilling to Flash.
Recommended
Audio Processing and PDM Microphones
The ATSAMD51J20A-AUT is well suited to edge-audio nodes that decode PDM microphone streams, run sample-rate conversion, and emit I2S/SAI to a codec. The I2S peripheral supports master/slave 48 kHz / 96 kHz sample rates and the PDM interface maps to a SERCOM in PDM mode. With 120 MHz CPU and DSP extensions, decimation filters and small FFTs run comfortably in real time. The 1 MB Flash holds audio processing libraries plus a UF2 bootloader for OTA firmware updates.
Recommended
IoT Edge Sensor with TLS Stack
For IoT edge devices that run TLS 1.3 to a cloud endpoint, the ATSAMD51J20A-AUT combines Cortex-M4F performance for crypto acceleration with 256 KB SRAM large enough to hold TLS session buffers and the mbedTLS or wolfSSL stack. The 1 MB Flash stores the TLS library plus application code and OTA slots. Multiple SERCOMs handle Wi-Fi or LoRa module UART/SPI plus a sensor I2C bus, and the RTC enables sleep modes down to a few microamps for battery operation.
Recommended
Automotive Body Control Module
The ATSAMD51J20A-AUT -AUT automotive temperature grade qualifies it for body-control applications in cabin environments operating from -40C to +85C. Its CAN-FD capability (via SERCOM + external transceiver) plus LIN master support enables body networks for lighting, mirror, and seat modules. With 1 MB Flash and 256 KB SRAM, the device holds CANopen / J1939 stacks plus application firmware, and the dual-bank Flash supports in-field OTA updates for body controllers.
Recommended
Industrial Touch Panel HMI
For industrial HMI panels combining capacitive touch sensing with TFT display driving, the ATSAMD51J20A-AUT provides parallel display interface plus a PTC peripheral for hardware-accelerated touch acquisition. The 120 MHz Cortex-M4F runs LVGL or emWin graphics stacks smoothly at typical 480x272 / 800x480 resolutions. With 1 MB Flash it holds graphical assets plus RTOS kernel (FreeRTOS or Zephyr), and the SERCOMs interface to Wi-Fi/BLE modules for cloud connectivity.
Recommended
Data Logger with SD Card Storage
The ATSAMD51J20A-AUT includes an HSMCI peripheral that interfaces directly to SD/MMC cards in 1-bit or 4-bit SD mode at up to 50 MHz clock. With 256 KB SRAM it can buffer several sectors during write bursts, while 1 MB dual-bank Flash supports a FAT/exFAT library plus application code. The RTC with calendar enables timestamped logs, and the ADC saturates analog inputs at 1 MSPS for high-fidelity data acquisition logging.
Recommended
Recommended Products Summary
Engineering reference data for ATSAMD51J20A-AUT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | ATSAMD51J20A-AU | ATSAMD51J19A-AUT | ATSAMD51J18A-AUT |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-TQFP (10x10 mm) | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same |
| Core | ARM Cortex-M4F, 120 MHz | ARM Cortex-M4F, 120 MHz | ARM Cortex-M4F, 120 MHz | ARM Cortex-M4F, 120 MHz |
| Flash Memory | 1 MB (1024 KB) | 1 MB (1024 KB) | 512 KB (-50%) | 256 KB (-75%) |
| SRAM | 256 KB | 256 KB | 256 KB | 128 KB (-50%) |
| Temperature Grade | -40C to +85C (automotive -AUT) | 0C to +70C (commercial -AU) | -40C to +85C (automotive) | -40C to +85C (automotive) |
| Supply Voltage | 1.71 V to 3.63 V | 1.71 V to 3.63 V | 1.71 V to 3.63 V | 1.71 V to 3.63 V |
| USB | FS USB 2.0 Device/Host | FS USB 2.0 Device/Host | FS USB 2.0 Device/Host | FS USB 2.0 Device/Host |
| Approx. Unit Price (USD, as of 2026-09-21) | $5.67 | ~$5.50 (similar to -AUT, both at 1 MB) | ~$4.80 | ~$4.30 |
Key Differentiators
- 1 MB dual-bank Flash for live OTA updates (vs ATSAMD51J19A-AUT)
- 256 KB SRAM for TCP/TLS stacks and audio buffers (vs ATSAMD51J18A-AUT)
- Automotive -AUT temperature grade (vs ATSAMD51J20A-AU)
Design Notes
Decouple every VDD and VDDIO pin with a 100 nF X7R ceramic capacitor placed within 5 mm of the pin, plus a bulk 4.7 uF tantalum or ceramic on each rail. SAM D51 has separate VDD (core) and VDDIO (I/O) supplies; both must be present for the device to start. For USB applications, route D+/D- as a 90-ohm differential pair and add a ferrite bead on the 3.3 V analog supply feeding the USB transceiver to avoid jitter.
Place a 32.768 kHz crystal between XIN32 and XOUT32 with 12-22 pF load capacitors for the RTC domain. For USB D+/D-, route the 90-ohm differential pair with matched length (within 150 mil), keep a continuous reference ground plane below, and avoid routing over power-plane splits. Place the SWD header (SWDIO, SWCLK, NRST, GND) on a 0.1 inch 2x5 connector for standard 10-pin ARM Cortex debug.
Do not exceed 3.63 V on VDDIO - the SAM D51 ESD clamping diodes will forward-conduct. Configure unused pins as outputs driven low (not high-Z) or enable the input-disable register in the PORT group to suppress parasitic current draw in sleep modes. The dual-bank Flash requires that the BOOTPROT region be set before enabling live update; otherwise a power-loss during write can brick the application. Use the SAM-BA or bossa bootloader to recover if this occurs.
The Cortex-M4F core switches 120 MHz with internal bus loads around 30 pF; use a 4-layer PCB with continuous ground plane and stitch the ground pours around the IC with 0.5 mm vias to reduce EMI. Keep SERCOM routed signals short, add 33 ohm series resistors on SPI SCK/MOSI/MISO if the bus exceeds 10 MHz, and reserve a footprint for a ferrite on the analog supply to ADC pins to suppress digital switching noise from corrupting ADC samples.
Compliance Information
RoHS compliant per Microchip product page. The -AUT suffix denotes automotive temperature grade (-40C to +85C) but not AEC-Q100 qualification; for AEC-Q100-qualified body modules choose ATSAMD51J20A-AUT-EFP or ATSAMD51J19A-AUT-EFP from the Site MPN list.
